The rubber hand is perceived as part of your own body when you can’t see your own. (CREDIT: © Damian Gorczany)
In a nutshell
- When people perceive a rubber hand as part of their body, it can reduce pain in their real hand, as shown in the study using visual-thermal stimulation.
- The pain-reducing effect of the illusion occurs as early as 1.5 seconds after the heat stimulus starts, offering potential for fast-acting pain relief.
- This research opens up possibilities for non-drug treatments for chronic pain, particularly through manipulating the brain’s perception of body ownership.
BOCHUM, Germany — Your brain is easily fooled, and that might be a good thing for pain relief. International researchers have found that when people are tricked into feeling that a rubber hand belongs to them, they experience less pain in their actual hand. This discovery opens up exciting possibilities for non-drug pain relief.
Research published in Pain Reports explored whether the rubber hand illusion could reduce pain, and if so, exactly when and how this happens. Earlier studies showed mixed results. Some found less pain, others found more pain, and some found no change at all.
This study took a fresh approach by using the same stimulus to both create the illusion and cause pain. Previous studies typically used one method (like brushing) to create the illusion and a different method to cause pain. Using a single stimulus meant participants could focus completely on one sensation rather than dividing their attention.
The rubber hand illusion works like this: a rubber hand sits in front of you while your real hand is hidden. When both the rubber hand and your hidden real hand are touched at the same time, your brain starts to feel that the rubber hand is actually part of your body.
Real-Time Pain Tracking Shows Quick Relief
For this study, instead of touching, researchers used heat and light. The study involved 34 right-handed participants who received heat on their hidden left hand while a rubber hand in front of them lit up red. Researchers tested four different heat levels: one warm but not painful temperature, and three increasingly painful heat levels.
During the experiment, participants constantly rated their pain using a sliding knob in their right hand. This let researchers pinpoint exactly when pain reduction happened.
When the rubber hand was positioned normally, pain ratings were lower than when the rubber hand was flipped upside-down. This pain-reducing effect showed up at almost all temperature levels tested.
Pain reduction kicked in early, about 1.5 seconds after heating began, and lasted throughout most of the stimulation period. This means the pain relief starts quickly and continues as long as the illusion is maintained.
“We showed that the perceived pain intensity was reduced in the rubber hand illusion condition compared to the control condition,” says lead study author Martin Diers from the Ruhr University Bochum, in a statement.
Oddly enough, the strength of the illusion stayed the same regardless of temperature. Participants felt the same level of ownership over the rubber hand whether the stimulation was mildly warm or painfully hot.
From Lab Trick to Potential Treatment
Pain is not just a simple sensory experience; it’s deeply influenced by psychological factors including our sense of body ownership. When we embody an artificial limb through this illusion, it appears to alter how pain signals are processed in the brain.
This suggests that pain is not just a direct response to physical stimuli but is actively constructed by the brain based on multiple sources of information, including visual cues and our sense of body ownership.
This could be due to what scientists call “visual analgesia.” This suggests that seeing the painful area or the relevant body part can alter the way pain is processed, potentially leading to a decrease in pain intensity.
This research opens new doors for pain management. If changing how we perceive our bodies can reduce pain, we might develop new non-drug approaches to treat chronic pain conditions.
“One potential application would be treating complex regional pain syndrome, where patients typically experience pain and swelling in the hand,” says Diers.
We once thought pain was simple: you get hurt, you feel pain. Now we know better. Our brains construct pain using whatever information is available, including what we see and believe about our bodies. This rubber hand study isn’t just a cool trick; it’s a glimpse into how we might someday hack our own pain perception to live better lives.
Paper Summary
Methodology
Participants sat at a table with their left hand on a temperature-controlled device, hidden from view. A rubber hand was placed visibly in front of them, capable of lighting up red from below. In standard trials, the rubber hand was positioned naturally; in control trials, it was rotated 180 degrees. Heat was applied to the hidden real hand while the rubber hand simultaneously lit up red. Participants continuously rated their pain using a sliding knob and later completed questionnaires about their experience of body ownership and pain.
Results
Participants reported stronger feelings of rubber hand ownership during normal positioning compared to when it was rotated. Continuous pain ratings were significantly lower during the rubber hand illusion for three of the four temperature levels tested (-0.75°C, moderate pain, and +1.5°C). Pain reduction began around 1.5 seconds after stimulation started and persisted throughout most of the stimulation period. Interestingly, post-experiment questionnaires didn’t show significant differences in pain ratings, suggesting real-time measurement captures effects that retrospective assessments miss.
Limitations
The study had a relatively small sample of 34 participants, mostly young adults. It focused exclusively on heat pain in healthy individuals, so results might not apply to other types of pain or to chronic pain patients. There was also a discrepancy between continuous and retrospective pain ratings, suggesting potential memory biases. The control condition (rotating the rubber hand) differs from the asynchronous stimulation control commonly used in RHI studies, making direct comparisons with previous research challenging.
Discussion and Takeaways
The pain-reducing effect across multiple temperature levels suggests this phenomenon is reliable. Using the same stimulus for both pain induction and creating the illusion ensures participants’ attention remains fully focused on the experiment. The time course analysis shows that pain reduction begins early and persists, offering new insights into when pain modulation occurs during the RHI. These findings could potentially lead to novel therapeutic approaches for chronic pain conditions, though more research is needed to determine if these effects translate to clinical populations.
Funding and Disclosures
The research was supported by the Department of Psychosomatic Medicine and Psychotherapy at LWL University Hospital, Ruhr University Bochum in Germany. The authors declared no conflicts of interest related to this study.
Publication Information
The study, “Time course of the rubber hand illusion–induced analgesia,” was published in Pain Reports in 2025. The research team included Benjamin Mosch, Xaver Fuchs, Theresia Tu, and Martin Diers from Ruhr University Bochum in Germany.
